Refer: https://www.howtogeek.com/350011/whats-new-in-ubuntu-18.04-lts-bionic-beaver-available-now/
Using Gnome: https://www.howtogeek.com/330941/what-unity-users-need-to-know-about-ubuntu-17.10s-gnome-shell/
Gnome getting window buttons back
It is not immediately obvious how to do this, with GNOME Tweak Tool having no easy-click option to move them, and many old forum answers no longer applying.
Install dconf-editor from the Software app and then navigate to org.gnome.desktop.wm.preferences.